Disk having unique code for identifying its type for optical disk player and method for discriminating types thereof

ABSTRACT

A BCA (Burst Cutting Area) code including a unique disk code indicating the type of a disk is written in a BCA code area of the disk. If the disk is mounted into the optical disk player, the optical disk player reads data written in the BCA code area, extracts the disk code contained in the read data, and confirms the type of the disk corresponding to the extracted disk code by retrieving a disk code table in which disk codes corresponding to the types of disks are mapped.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of Korean Application No.80595/1997, filed Dec. 31, 1997, in the Korean Patent Office, thedisclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to an optical disk player, and moreparticularly, to a method for discriminating the type of a disk mountedinto an optical disk player.

[0004] 2. Description of the Related Art

[0005] An optical disk player reproduces data recorded on an opticaldisk, such as a CD (Compact Disk), CD-ROM (Compact Disk-Read OnlyMemory), LD (Laser Disk), MD (Mini Disk), DVD (Digital Video Disk), etc.Since there are various types of optical disks, the optical disk playershould discriminate the type of a disk mounted therein. Especially, aDVD player which uses a CD-series disk as well as a DVD-series disk maynot accurately reproduce data unless it determines which type of disk ismounted therein.

[0006] Referring to FIG. 1, an optical pickup 102 optically picks upinformation recorded on a disk and generates an electrically convertedRF (radio frequency) signal. The optical pickup 102 has a focusingactuator and a tracking actuator. The focusing actuator is driven by thecontrol of a DSSP (Digital Servo Signal Processor) 114 and shifts anobject lens toward an optical axis. The tracking actuator shifts theobject lens toward the radial direction of a disk 100 to seek a track. Aspindle motor 104 is driven under the control of the DSSP 114 to rotatea disk 100 at a CLV (Constant Linear Velocity). A sled feed motor 106 isdriven under the control of the DSSP 114 to move the optical pickup 102.

[0007] An RF amplifier 108 amplifies the RF signal received from theoptical pickup 102 and shapes a waveform of the amplified RF signal. TheRF amplifier 108 supplies a modulation signal during writing to a DSP(Digital Signal Processor) 110 and supplies signals for tracking servoand focusing servo to the DSSP 114. If the disk 100 is a CD-series disk,the modulation signal is an EFM (Eight to Fourteen Modulation) signal.If the disk 100 is a DVD-series disk, the modulation signal is an EFMplus signal. The DSP 110 also restores a BCA (Burst Cutting Area) codereproduced from a BCA code area on the disk 100. An output processor 112processes the data generated from the DSP 110 and generates a finaloutput signal such as an audio signal. The DSSP 114, controlled by amicrocomputer 116, controls tracking servo and focusing servo of theoptical pickup 102, sled servo using the sled feed motor 106, andspindle servo, in response to signals received form the RF amplifier 108and the DSP 110. The microcomputer 116, which is a main controller,controls the overall operation of an optical disk player.

[0008]FIG. 2 illustrates a general BCA code structure. The BCA code iscomprised of a BCA preamble 200, BCA information data I_(BCA) 202, anerror detecting code EDC_(BCA) 204, and error correcting code ECC_(BCA)206, and a BCA postamble 208. The BCA code is written in the disktogether with a corresponding synchronizing byte. That is, the 4-byteBCA preamble 200 is written in the disk together with a BCAsynchronizing byte SB_(BCA). The BCA information data I_(BCA) 202, theerror detecting code EDC_(BCA) 204, the error correcting code ECC_(BCA)206, and the BCA postamble 208 are written in the disk together with aBCA re-synchronizing byte RS_(BCA).

[0009] The BCA information data I_(BCA) 202 (I_(O)-I_(16n-5)) can beexpressed by the following equation (1). The error detecting codeEDC_(BCA) 204 (ED₀-ED₃) is a parity for detecting an error of the BCAinformation data I_(BCA) 202 and is expressed by the following equations(2) and (3) and as the remainder obtained by dividing input dataI_(BCA)(x) by a polynomial G(x) which can be expressed by the followingequation (4). A bit operation is expressed using a small letter ‘x’.$\begin{matrix}{{I_{BCA}(x)} = {\sum\limits_{i = 32}^{{128n} - 1}{{bi} \cdot x^{i}}}} & (1)\end{matrix}$

$\begin{matrix}{{{EDC}_{BCA}(x)} = {\sum\limits_{i = 0}^{31}{{bi} \cdot x^{i}}}} & (2)\end{matrix}$

EDC_(BCA)(x)=I_(BCA)(x)modG(x)   (3)

G(x)=x ³² +x ³¹ +x ⁴+1   (4)

[0010] The error correcting code ECC_(BCA) 206 (C_(0,0)-C_(3,3)) is aparity for correcting errors of the BCA information data I_(BCA) 202 andthe error detecting code EDC_(BCA) 204 and is expressed as the remainderobtained by dividing input data I_(BCAj)(x) by a polynomial G_(pBCA)(x)as shown in the following equations (5)-(9). A byte operation isexpressed using a capital letter ‘X’. $\begin{matrix}{{R_{BCAj}(X)} = {\sum\limits_{i = 0}^{3}{C_{j,i} \cdot X^{3 - i}}}} & (5) \\{{D_{BCAj}(X)} = {{\sum\limits_{i = 0}^{{4n} - 2}{I_{j + {4i}} \cdot X^{51 - i}}} + {{ED}_{j} \cdot X^{52 - {4n}}}}} & (6)\end{matrix}$

ECC_(BCAj)(X)=I_(BCAj)(X)modG_(pBCA)(X)   (7)

[0011] $\begin{matrix}{{G_{pBCA}(X)} = {\prod\limits_{k = 0}^{3}\left( {X + a^{k}} \right)}} & (8)\end{matrix}$

GP(x)=x ⁸ +x ⁴ +x ³ +x ²+1   (9)

[0012] On the other hand, as shown in the BCA code structure of FIG. 2,there is a re-synchronizing byte RS_(BCA1) area which is not used in theBCA code area. That is, the BCA code is written in the BCA code area ofa lead-in area on the disk and there is an unused re-synchronizing bytearea in the BCA code area. In the present invention, the BCA codeincluding a disk code is written in the disk. Therefore, the BCA codeincludes the disk and the disk having the disk code in the BCA code areaperforms the normal operation in the optical disk player.

[0013] A conventional method for discriminating the type of a disk usedin the DVD player will now be described. If the user inserts theDVD-series or CD-series disk into the DVD player and a tray is closed,the DVD player sets its operating mode to a CD mode and starts focussearching. During the focus searching, the DVD player checks whetherthere is a focus error. If two focus error signals are respectivelygenerated in the up and down movement directions of a lens, the DVDplayer judges the inserted disk to be a dual layer disk. If one focuserror signal is generated, the inserted disk is regarded as a singlelayer disk. If focusing has ended, the DVD player rotates a spindlemotor and checks a phase difference between E and F signals detected byan E/F photo diode of an optical pickup. If the phase difference is180°, the inserted disk is judged to be the CD-series disk, and if thereis no phase difference, it is regarded as the DVD-series disk.Thereafter, the DVD player checks a lead-in area of the disk todistinguish a V-CD (video CD), a CD-audio from the CD-series disk, andDVD-single, DVD-dual from the DVD-series disk. Thus, the diskdiscriminating operation is completed. This operation is controlled by amicrocomputer which is a main controller of the DVD player.

[0014] Meanwhile, since the above-described disk discriminatingoperation is performed step by step, the microcomputer passes throughmany steps for detecting the type of disk. Therefore, the load on themicrocomputer increases, and it takes a lot of time to discriminate thetype of the disk. If the disk discriminating process has not ended in ashort time period, a waiting time until a normal playback state isperformed may be very long. Moreover, a check as to whether the disk isa dual layer or a single layer is made by using the focus error signal,and a determination as to whether the disk is the CD-series or theDVD-series is made from the phase difference between the E and F signalsby utilizing the fact that a track pitch of the CD-series disk isdifferent from that of the DVD-series disk. Therefore, if the disk hasscratches, the disk player may wrongly detect the type of the disk. Whenconsidering future optical disk which will be put on the market, itbecomes very difficult to discriminate the type of the disk and there isa strong possibility that the type of the disk is wrongly detected.

SUMMARY OF THE INVENTION

[0015] It is an object of the present invention to provide a disk havinga unique code for identifying its type for an optical disk player and amethod for rapidly and accurately discriminating the type thereof.

[0016] Additional objects and advantages of the invention will be setforth in part in the description which follows and, in part, will beobvious from the description, or may be learned by practice of theinvention.

[0017] The foregoing and other objects of the present invention areachieved by providing a disk used in an optical disk player whichincludes a BCA (Burst Cutting Area) code area in which a BCA code iswritten. The BCA code area includes a preamble area in which a BCApreamble is written; an information data area in which BCA informationdata is written; an information data area in which BCA information datais written; an information parity area in which an error detection codefor the BCA information data is written; a disk code area in which aunique disk code indicating the type of the disk is written; a codeparity area in which an error detecting code for the disk code iswritten; an error correcting parity area in which an error correctingcode for the BCA information data, for the error detecting code of theBCA information data, for the disk code and for the error detecting codeof the disk code is written; and a postamble area in which a BCApostamble is written. The BCA code area is arranged in the order of thepreamble area, information data area, information parity area, disk codearea, disk code parity area, error correcting parity area, and postamblearea.

[0018] The BCA code area is situated in the innermost area of lead-inarea on the disk and represents an area in which the BCA code iswritten. Although the BCA code has not yet defined as being used for aspecific purpose, it may be used as a disk ID (Identification). A parityfor error detection is typically called an error detecting code (EDC)and a parity for error correction is called an error correcting code(ECC).

[0019] The above and other objects of the present invention may also beachieved with a method for discriminating the type of a disk in anoptical disk player which includes the steps of reading data written ina BCA code area upon mounting the disk into the optical disk player;extracting a disk code contained in the read data; confirming the typeof the disk corresponding to the extracted disk code by retrieving adisk code table in which disk codes corresponding to the types of disksare mapped.

[0020] The disk code table is stored in a nonvolatile memory of theoptical disk player by a manufacturer.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The above and other objects and advantages of the invention willbecome apparent and more readily appreciated from the followingdescription of the preferred embodiments, taken in conjunction with theaccompanying drawings of which:

[0022]FIG. 1 is a block diagram of a conventional optical disk player;

[0023]FIG. 2 shows a general BCA code structure;

[0024]FIG. 3 shows a BCA code structure according to an embodiment ofthe present invention; and

[0025]FIG. 4 is a flow chart showing a disk discriminating processaccording to the embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Reference will now made in detail to the present preferredembodiments of the present invention, examples of which are illustratedin the accompanying drawings, wherein like reference numerals refer tothe like elements throughout. The embodiments are described below inorder to explain the present invention by referring to the figures.

[0027] In the following description, numerous specific details, such asa BCA code structure, a processing flow, equations, and the like, areset forth to provide a more thorough understanding of the presentinvention. It will be apparent, however, to one skilled in the art, thatthe present invention may be practiced without these specific details.In other instances, well known functions or constructions have not beendescribed so as not to obscure the present invention.

[0028]FIG. 3 illustrates a BCA code structure according to an embodimentof the present invention. The BCA code shown in FIG. 3 includes a BCApreamble 200, BCA information data I_(BCA) 202, an error detecting codeEDC_(BCA) 204, a disk code I_(DDT) 210, an error detecting codeEDC_(DDT) 212, an error correcting code ECC_(BCA) 214, and a BCApostamble 208. In FIG. 3, the BCA code includes the disk code I_(DDT)210 and the error detecting code EDC_(DDT) 212 in addition to the BCAcode shown in FIG. 2, and the error correcting code ECC_(BCA) ismodified. The BCA code is written in the disk together with acorresponding synchronizing byte. That is, the 4-byte BCA preamble 200is written in the disk together with a BCA synchronizing byte SB_(BCA).The BCA information data I_(BCA) 202, the error detecting code EDC_(BCA)204, the disk code I_(DDT) 210, the error detecting code EDC_(DDT) 212,the error correcting code ECC_(BCA) 214, and the BCA postamble 208 arewritten in the disk together with a BCA re-synchronizing byte RS_(BCA).Therefore, the disk code I_(DDT) 210 and the error detecting codeEDC_(DDT) 212 are inserted into the BCA code, and the error correctingcode ECC_(BCA) 214 and the BCA postamble 208 follow them. This ispossible because the existing BCA code structure includes the unusedre-synchronizing byte area.

[0029] The BCA information data I_(BCA) 202 (I₀-I_(16n-5)) is expressedby the above equation (1). The error detecting code EDC_(BCA) 204(ED₀-ED₃) is a parity for detecting an error of the BCA information dataI_(BCA) 202 and is expressed by equation (2) as the remainder obtainedby dividing the BCA information data I_(BCA) 202 by the polynomial G(x)as indicated in the above equation (3).

[0030] The disk code I_(DDT) 210 indicating the type of the disk isexpressed by the following equation (10). The 4-byte error detectingcode EDC_(DDT) 212 (se the following equation (11)) is a parity fordetecting an error of the disk code I_(DDT) 210 and can be expressed asindicated in the following equation (12) as the remainder obtained bydividing the disk code I_(DDT)(x) by a polynomial G(x) G(x) can beexpressed by the following equation (13). $\begin{matrix}{{I_{DDT}(x)} = {\sum\limits_{i = 32}^{127}{{di} \cdot x^{i}}}} & (10) \\{{{EDC}_{DDT}(x)} = {\sum\limits_{i = 0}^{31}{{di} \cdot x^{i}}}} & (11)\end{matrix}$

EDC_(DDT)(x)=I_(DDT)(x)modG(x)   (12)

G(x)=x³² +x ³¹ +x ⁴+1   (13)

[0031] The error correcting code ECC_(BCA) 214 (C_(0,0)-C_(3,3)) is aparity for correcting errors of the BCD information data I_(BCA) 202,the error detecting code EDC_(BCA) 204, the disk code I_(DDT) 210 andthe error detecting code EDC_(DDT) 212 and can be expressed as theremainder obtained by dividing input data I_(BCAj)(x) by a polynomialG_(pBCA)(x) as indicated in the following equations (14) through (18).$\begin{matrix}{{{EDD}_{BCA}(X)} = {\sum\limits_{i = 0}^{3}{C_{j,i} \cdot X^{3 - i}}}} & (14) \\\begin{matrix}{{D_{BCA}(X)} = \quad {{\sum\limits_{I = 0}^{{4n} - 2}{I_{j + {4i}} \cdot X^{55 - i}}} + {{ED}_{j} \cdot X^{56 - {4n}}} +}} \\{\quad {{\sum\limits_{k = 0}^{2}{{DT}_{j,k} \cdot X^{7 - k}}} + {{EDT}_{j} \cdot X^{4}}}}\end{matrix} & (15)\end{matrix}$

ECC_(BCAj)(X)=D_(BCAj)(X)modG_(pBCA(X))   (16)

[0032] $\begin{matrix}{{G_{pBCA}(X)} = {\prod\limits_{m = 0}^{3}\left( {X + a^{m}} \right)}} & (17)\end{matrix}$

Gp(x)=x ⁸ +x ⁴ +x ³ +x ²+1   (18)

[0033] The BCA code having the above-mentioned structure is sequentiallywritten in the BCA code area on the disk. Therefore, the BCA code areain which the BCA code including the disk code is written has a preamblearea in which the BCA preamble is written; and information data area inwhich the BCA information data is written; and information parity areain which the error detection code for the BCA information data iswritten; a disk code area in which a unique disk code indicating thetype of the disk is written; a disk code parity area in which the errordetecting code for the disk code is written; an error correcting parityarea in which the error correcting code for the BCA information data,for the error detecting code of the BCA information data, for the diskcode and for the error detecting code of the disk code is written; and apostamble area in which the BCA postamble is written. The BCA code areais arranged in the order of the preamble area, the information dataarea, the information parity area, the disk code area, the disk codeparity area, the error correcting parity area, and the postamble area.

[0034]FIG. 4 illustrates a disk discriminating process using the diskcode when the disk in which the BCA code is written is mounted into theoptical disk player. This process if performed by the microcomputer 116shown in FIG. 1. If the disk 100 having the BCA code area in which theBCA code of FIG. 3 is written is mounted into the optical disk player ofFIG. 1 at step 400, the microcomputer 116 reads data written in the BCAcode area on the disk 100 at step 402. The read data is restored by theDSP 110. The microcomputer 116 extracts the disk code contained in theread data through the DSP 110 at step 404. The microcomputer 116confirms the type of the disk corresponding to the extracted disk codeby retrieving a disk code table at step 406. The disk code table isprovided from a manufacturer by previously mapping the disk codescorresponding to the types of disks and stored in a nonvolatile memoryof the microcomputer 116.

[0035] Consequently, a unique disk code corresponding to the type of adisk is previously written in the disk and the type of the disk isdiscriminated by using the disk code. Therefore, the type of the diskmounted into the optical disk player can be rapidly and accuratelydetected. Since the disk code and its error detecting code are insertedinto the re-synchronizing byte area which is not used in the existingBCA code structure, the added codes have no effect on the existing BCAcode and the inventive disk can perform the normal operation.

[0036] As mentioned above, the type of the disk mounted into the opticaldisk player can be rapidly and accurately detected by using the diskcode contained in the BCA code.

[0037] While the invention has been shown and described with referenceto a certain preferred embodiment thereof, it will be understood bythose skilled in the art that various changes in form and details may bemade therein without departing from the spirit and scope of theinvention as defined by the appended claims and that it may be possible,for example, to modify the number of bytes of the BCA code or the diskcode and to differently apply the polynomial or the parity.

What is claimed is:
 1. A disk for an optical disk player, comprising: alead-in area; a BCA (Burst Cutting Area) code area in which a BCA codeis written, said BCA code area being situated in the lead-in area andincluding: a preamble area in which a BCA preamble is written; aninformation data area in which BCA information data is written; aninformation parity area in which an error detecting code for said BCAinformation data is written; a disk code area in which a unique diskcode indicating a type of said disk is written; a disk code parity areain which an error detecting code for said disk code is written; an errorcorrecting parity area in which an error correcting code for said BCAinformation data, for said error detecting code of said BCA informationdata, for said disk code and for said error detecting code of said diskcode is written; and a postamble area in which a BCA postamble iswritten; wherein said BCA code area is arranged in an order of saidpreamble areas, information data area, information parity area, diskcode area, disk code parity area, error correcting parity area andpostamble area.
 2. An optical disk usable with an optical disk player,comprising: a BCA (Burst Cutting Area) code area in which a BCA code iswritten, the BCA code including BCA information and a disk codeindicating a type of said disk.
 3. The optical disk as claimed in claim2, wherein said BCA code area comprises a re-synchronizing byte areaincluding the BCA information, the disk code and a corresponding BCAre-synchronizing byte.
 4. The optical disk as claimed in claim 3,wherein said re-synchronizing byte area comprises: a preamble area inwhich a BCA preamble is written; an information data area in which theBCA information is written; an information parity area in which an errordetecting code for the BCA information is written; a disk code area inwhich the disk code is written; a disk code parity area in which anerror detecting code for the disk code is written; an error correctingparity area in which an error correcting code for the BCA information,for the error detecting code of the BCA information, for the disk code,and for the error detecting code of the disk code is written; and apostamble area in which a BCA postamble is written.
 5. The optical diskas claimed in claim 4, wherein said BCA code area further comprises asynchronizing byte area including a BCA preamble and a corresponding BCAsynchronizing byte.
 6. The optical disk as claimed in claim 3, whereinsaid re-synchronizing code area comprises: a disk code area in which thedisk code is written; a disk code parity area in which an errordetecting code for the disk code is written; an error correcting parityarea in which an error correcting code for the disk code and for theerror detecting code of the disk code is written.
 7. The optical disk asclaimed in claim 2, further comprising a lead-in area which includes theBCA code area.
 8. The optical disk as claimed in claim 6, furthercomprising a lead-in area which includes the BCA code area.
 9. Theoptical disk as claimed in claim 4, wherein the disk code (I_(DDT)), andthe error detecting code (EDC_(DDT)) which is a parity for detecting anerror of the disk code are expressed according the following equations,${{I_{DDT}(x)} = {\sum\limits_{i = 32}^{127}{{di} \cdot x^{i}}}};$${{EDC}_{DDT}(x)} = {\sum\limits_{i = 0}^{31}{{di} \cdot x^{i}}}$

EDC_(DDT)(x)=I_(DDT)(x)modG(x); and G(x)=x ³² +x ³¹ x ⁴+1; wherein G(x)is a polynomial.
 10. The optical disk as claimed in claim 6, wherein thedisk code (I_(DDT)), and the error detecting code (EDC_(DDT)) which is aparity for detecting an error of the disk code are expressed accordingthe following equations, wherein G(x) is a polynomial.${{I_{DDT}(x)} = {\sum\limits_{i = 32}^{127}{{di} \cdot x^{i}}}};$${{{EDC}_{DDT}(x)} = {\sum\limits_{i = 0}^{31}{{di} \cdot x^{i}}}};$

EDC_(DDT)(x)=I_(DDT)(x)modG(x); and G(x)=x ³² +x ³¹ +x ⁴+1; wherein G(x)is a polynomial.
 11. The optical disk as claimed in claim 9, wherein theerror correcting code (ECC_(BCA)), which is a parity for correctingerrors of the BCA information, and the error detecting code (EDC_(BCA)),which is a parity for detecting an error of the BCA information, thedisk code (I_(DDT)), and the error detecting code (EDC_(DDT)) for thedisk code, are expressed according the following equations,${{{ECC}_{BCA}^{*}(X)} = {\sum\limits_{i = 0}^{3}{C_{j,k} \cdot X^{3 - i}}}};$$\begin{matrix}{{D_{BCA}(x)} = \quad {{\sum\limits_{I = 0}^{{4n} - 2}{I_{j + {4i}} \cdot x^{55 - i}}} + {{ED}_{j} \cdot X^{56 - {4n}}} +}} \\{\quad {{{\sum\limits_{k = 0}^{2}{{DT}_{j,k} \cdot X^{7 - k}}} + {{EDT}_{j} \cdot X^{4}}};}}\end{matrix}$

ECC_(BCAj)(X)=D_(BCAj)(X)modG_(pBCA)(X);${{G_{pBCA}(X)} = {\underset{m = 0}{\overset{3}{\Pi}}\left( {X + a^{m}} \right)}};{and}$

Gp(x)=x ⁸ +x ⁴ +x ³ +x ²+1; wherein G(x) is a polynomial, x is a bitoperation and X is a byte operation.
 12. A method of discriminating atype of a disk in an optical disk player, said disk having a BCA (BurstCutting Area) code area in which a BCA code including a unique disk codeis written, said method comprising the steps of: reading data written insaid BCA code area subsequent to mounting said disk into said opticaldisk player; extracting the disk code contained in the read data; andconfirming the type of said disk corresponding to the extracted diskcode by retrieving a disk code table in which a plurality of disk codescorresponding to a plurality of types of disks are mapped.
 13. A methodfor discriminating the type of a disk used in an optical disk player,comprising the steps of: writing a BCA (Burst Cutting Area) codeincluding a unique disk code indicating a type of said disk in a BCAcode area defined in a lead-in area of said disk; reading data writtenin said BCA code area upon mounting said disk into said optical diskplayer; extracting the disk code contained in the read data; andconfirming the type of said disk corresponding to the extracted diskcode by retrieving a disk code table in which a plurality of disk codescorresponding to a plurality of types of disks are mapped.
 14. Themethod as claimed in claim 13, wherein said writing step comprises thesteps of: writing a BCA preamble in a preamble area situated at a frontof said BCA code area; writing BCA information data in an informationdata area of said BCA code area and following said preamble area;writing an error detection code for said BCA information data in aninformation parity area of said BCA code area and following saidinformation data area; writing a unique disk code indicating a type ofsaid disk in a disk code area of said BCA code area and following saidinformation parity area; writing an error detecting code for said diskcode in a disk code parity area of said BCA code area and following saiddisk code area; writing an error correcting code for said BCAinformation data, for said error detecting code of said BCA informationdata, for said disk code and for said error detecting code of said diskcode in an error correcting parity area of said BCA code area andfollowing said disk code parity area; and writing a BCA postamble in apostamble area of said BCA code area and following said error correctingparity area.
 15. An optical disk player for discriminating a type of anoptical disk loaded in the optical disk player, wherein the optical diskhas a Burst Cutting Area (BCA) which stores a BCA code including a diskcode indicating the type of disk, the optical disk player comprising: anoptical pickup to retrieve an information signal including the BCA codefrom the optical disk; an amplifier to amplify the information signalincluding the BCA code; a digital signal processor (DSP) to demodulatethe amplified information signal including the BCA code; and aprocessing unit to extract the disk code from the BCA code of thedemodulated amplified information signal, to retrieve a disk code tablehaving disk codes corresponding to a plurality of different types ofoptical disks previously stored therein, and to determine the type ofthe optical disk loaded in the optical disk player by comparing the diskcode with the disk code table.
 16. The optical disk player as claimed inclaim 15, wherein the BCA code area includes a BCA preamble, BCAinformation, an error detecting code for the BCA information, the diskcode, an error detecting code for the disk code, an error correctingcode for the BCA information, for the error detecting code of the BCAinformation, for the disk code and for the error detecting code of thedisk code, in order, and said processing unit determines the disk codeto be following the error detecting code of the BCA information andbefore the error detecting code for the disk code.